Icing and snow accretion preventive insulator, electric wire, and antenna, method for manufacturing them, and transmission line tower using them

Abstract

Conventional chemisorption films use only a chemical bond between an adsorbent and a flat base material surface and thus have a problem that the contact angle of water droplets is about 120 degrees at the highest and, thus, water-repellent, oil-repellent and anti-fouling properties and water take-off properties are unsatisfactory for spontaneous removal of water droplets and dirt as in a lotus leaf. This invention provides an icing and snow accretion preventive insulator, electric wire and antenna. They are manufactured by a method characterized by comprising at least the step of forming a fine particle fusion film on the surface of a base material, the step of coating a fine particle liquid, prepared by dispersing fine particles in a solvent which does not dissolve the film, and drying the coating, the step of firing, the step of removing, by washing, fine particles not fused to the film, and the step of forming a water-repellent, oil-repellent and anti-fouling film. Alternatively, they may be manufactured by a method characterized by comprising at least the step of coating a fine particle liquid, prepared by dispersing fine particles in a solvent, onto the surface of a base material and drying the coating, the step of firing, the step of removing, by washing, fine particles not fused to the film, and the step of forming a water-repellent, oil-repellent and anti-fouling film.

The invention claimed is: 
     
       1. An icing and snow accretion preventive system comprising:
 an insulator composed at least in part of a base material; 
 an electric wire; and 
 an antenna; 
 wherein a surface of the base material is coated with: 
 water-repellent, oil-repellent, and antifouling first fine particles and water-repellent, oil-repellent, and antifouling second fine particles, wherein the first fine particles and the second fine particles are fused to the base material, wherein the first fine particles are larger than the second fine particles, and wherein a first portion of the surface of each of the first fine particles and the second fine particles are fused to be fixed on the surface of the base material, and 
 a water-repellent, oil-repellent, and antifouling coating film coating the first fine particles, the second fine particles, and the base material. 
 
     
     
       2. The icing and snow accretion preventive system according to  claim 1 , wherein a second portion, different from the first portion, of the surface of each of the fused water-repellent, oil-repellent, and antifouling first fine particles and second fine particles are coated with the water-repellent, oil-repellent, and antifouling coating film. 
     
     
       3. The icing and snow accretion preventive system according to  claim 1 , wherein the second fine particles have diameters between 10 and 500 nanometers and the first fine particles have diameters between 1 and 100 micrometers. 
     
     
       4. The icing and snow accretion preventive system according to  claim 1 , wherein molecules of the coating film are covalently bonded to each of the first fine particles, the second fine particles, and the base material. 
     
     
       5. The icing and snow accretion preventive system according to  claim 4 , wherein the water-repellent, oil-repellent, and antifouling coating film contains a —CF 3  group. 
     
     
       6. The icing and snow accretion preventive system according to  claim 1 , wherein the first fine particles and the second fine particles are made of a resin, metal, or ceramic having a softening temperature higher than the softening temperature of the base material or the softening temperature of a fusion film on the surface of the base material. 
     
     
       7. The icing and snow accretion preventive system according to  claim 1 , wherein a contact angle of water on the surface is controlled to be 150 degrees or more. 
     
     
       8. The icing and snow accretion preventive system according to  claim 1 , wherein a fusion film exists on the base material, the first fine particles and the second find particles are fused to the fusion film, and the fusion film is composed of a resin film, a silica glass film, or a glaze film. 
     
     
       9. The icing and snow accretion preventive system according to  claim 1 , wherein the first fine particles and the second fine particles are fused directly to the base material, and the base material is made of a ceramic, copper, or aluminum. 
     
     
       10. The icing and snow accretion preventive system according to  claim 1 , wherein the system comprises a transmission line tower.